Variable impulse transmitter



April 4, 1950 G. DEAKIN VARIABLE IMPULSE TRANSMITTER 11 sheets-sheet 1 Filed Jan.' 21, 1947 1 NVEN TOR. GBP/ILD DE/K//V ATTORNEYS INVENTOR GEWILD DE/M//A/ ATTORNEYS LKJ H FED CBA G DEAKIQ VABIABLE MPULSE TRANSMITTER A IApril 4, 1950 l Filed Jan. 21, 1947 April 4, 1950 G. DEAKIN VARIABLE IMPULsE TRANSMITTER Filed Jan. 21, 1947 A l 1l Sheets-Sheet 3 INVENTOR. GER/MD EK//V ATTORNEYS April 4, 1950 4 -G. DEAKIN VARIABLE IMPULSE' TRANSMITTER 'Filed han.' 21, i947 11 Sheets-sheet 4 v@V A@ INVENTOR. ammo off/mv WM W S v.. E. N Dn O T. T. A

April 4, 1950 l G. DEAKIN 2,502,440

VARIABLE, IMPULsE TRANSMITTER Filed Jan. 21, v1947 11 sheets-snaai 5 1055 I i o5 ATToRNm/s .April 4,1950 A u. GfDEAKlN I 2,502,440

` VARIABLE IMPULSE TRANSMITTER y Filed Jan. 21. 1947 11 Sheets-Sheet 6 April 4, 1950 G. DEAKIN VARIABLE IMPuLsE TRANSMITTER 1l Sheets-Sheet '7 Filed Jan. 21, '1947 15 INVENTOR. N5 GER/1z0 afa/IN ATTORNEYS April 4, 1950 4 G, DEAKlN I '2,502,440

VARIABLE IMPULSE TRANSMITTER med Jan. 21, 1947 11 sheets-sheet zav fold i 101e e fnac 'GERALD affix/N l -ATTORNEYS Filed Jan. 21, 1947 11 Sheets-Sheet 9 April 4, 1950 G. DEAKIN 2,502,440

VARIABLE IMPULsE TRANSMITTER l INVENTOR. @fR/:Lo 05AM/v ATTORNEYS April 4, 1950 G. DEAKIN 2,502,440

VARIABLE IMPULsE TRANSMITTER v Filed Jan. 21, 1947 11 sheets-sheet 1o 1 NVEN TOR. GER/ILD EK//V ATTORNEYS lPatented pr. 4, 1950 2,502,440 VARIABLE IMPULSE TRANSMITTER Gerald Deakin, New York, N. Y., assignor to International Standard Electric Corporation, New York, N. Y., a corporation of Delaware Application January 21, 1947, Serial No. 723,446

22 Claims.

f This invention relates to new and useful improvements in electrical signalling and switching Vsystems and more particularly to improved pulse sending devices for use in telecommunication switching systems such as automatic and semiautomatic telephone exchanges.

LAn important object of the invention is to pro- 'vide novel and advantageous means for increasing the speed and ease with which the setting of switching means such as that for a numerical selector, may be effected. As in my co-pending application Serial No. 527,921, led March 24, 1944, now Patent No. 2,433,347 issued December 30, 1947, a total of ten diierent numerical settings are selectively controlled by sending positive and negative pulse combinations consisting of less than ten pulses. Each pulse combination consists of one to a maximum of five pulses and these pulse combinations are divided into two groups: leach combination of one group beginning with a positive pulse and each combination of the other group beginning with a negative pulse. One of these groups may represent even and the other odd numbers. The dial used is moved clockwise to different extents tov start the recording of digits l through by pulse combinations produced in the return movement, starting with a, single positive pulse for the digit 1 and ending for the digit 5 with a combination of live alternating positive and negative pulses beginning with a positive pulse. For the digits 6 through 0, the dial is moved counterclockwise to produce pulse combinations starting for the digit 6 with a five-pulse combination beginning with a negative pulse and ending for the digit 0 with a single pulse which is negative.

Another object of the invention is to provide a2novel and advantageous pulse sending device producing positive and negative pulses. pulse sending apparatus, there are two side-byside rows of keys or linger pulls, the right-hand row of keys corresponding from the bottom to the top to digits 1 through 5 and the left-hand row of keys corresponding from the top to the bottom to digits 6 through 0. The arrangement of keys according to the present invention is much less likely to cause confusion than where In this the digits are arranged along arcs of a circle and v er, for each row of keys, whereas in said copending application there is but one rectier used. A The impulse sender is particularly yadapted to facilitate rapid operation thereof.

Other objects, features and advantages will appear upon consideration of the following detailed description and of the drawings, in which Fig. 1 is a side elevation of a sender or subscribers instrument embodying one form of the invention, certain parts being shown in dotted lines and others in -dot-and-dash lines;

Fig. 2 isa top plan view of the instrument shown in Fig. l;

Fig. 3 is a side elevation of the apparatus 0I Fig. 9, viewed from the right and with certain parts broken away; l

Fig. 4 is a sectional detail View of a sector for operating the main shaft of one unit of the sender;

Fig. 5 is a section taken on the line 5 5 of Fig. 4; p

Fig. 6 is a view of one of the finger-grip or key links;

Fig. 7 is a view similar to Fig. 3 but showing parts which were broken away in Fig. 3; j

Fig. 8 is a view illustrating the contact springs of the right hand unit as viewed from above;

` Fig. 9 is a front elevation partly in section and on a larger scale, of the two circuit-controlling units;

Fig. 10 is a diagrammatic view illustrating the manner in which the contact springs of the two unitsl are operated and the circuits controlled thereby;

Fig. 11 is a table illustrating the pulse com'- binations for the various digits;

Fig. 12 is a view in side elevation, somewhat similar to Fig. 3, but illustrating another form of the invention. l

Fig. 13 is a front elevation of the apparatus of Fig. 12 with certain parts broken away.

Fig. 14 isa fragmentary view on a larger scale of certain parts of Fig. 13 with other parts broken away, to illustrate the cooperation of the rectifier contact arms with the commutator;

Fig. 15 is a fragmentary top plan view of the contact springs of the right-hand unit and the means for. controlling the same; .f

Fig. 16 is a side elevation of the structure shown in Fig. 15;

Fig. 17' is a diagrammatic top plan view of th springs of the right-hand unit, the operating arm or pointer being in home position;

Fig. 18 is a' diagrammatic view illustrating the position of the springs when the pointerhas been moved to its front position and then returned to a position where it has closed one of the contact sets;

Fig. 19 is a view showing another set of con-` tacts closed and still another opened; and

Fig. 20 is a view showing one of the main contacts opened and a further contact closed, prior to releaseof all springs from control by a pin or pointer.

Referring to Figs. 1 through 11 of the dra ings, a base or stand of a subscribers set or sender embodying one form of the invention, is illustrated in side elevation in Fig. 1 and in top plan View in Fig. 2. As indicated in Fig. 1 a hand set 26 normally rests on the top 21 of a usual plunger assembly and in a cradle comprising upwardly projecting arms or posts 28.

Said stand 25 includes a frame 29 with a bottom 30 supported by members or feet 3|. Said bottom provides a peripheral ledge 32 on which rest recessed lower edges of a cover 33. This cover is preferably integral and open at one point for the plunger of the plunger assembly controlled by said hand set at removal and replacement, and at two parallel slots 34 through each `of which is normally displayed a row of ve individual n'ger grip keys 35 and two ush spacers M35 in advance thereof. In connection with starting a call nger grip keys 35 are drawn forward ,inthe proper order.

Said cover 32 includes a rectangular lower part resting on said ledge 32 and extending upwardly to an inturned ledge 3l. Above 'this ledge 31 is .an inwardly inclined rear wall 38, a lower front wall 39, inwardly inclined side walls '40 having "r'ear portoins of their upper edges parallel to their lower Aedges and front portions downwardly inclined' to the top of said front wall 39,and a top 41 having a horizontal rear portion carryving, said posts 28 ofthe cradle and a downwardly inclined front portion containing said slots 34 which are separated by a strip 42.

The five nger grip keys 35 in the right hand row, taken in order from front to rear (Fig. 2), bear, respectively vthe numerals 1, 2, 3, "4 `and 45 'and in the left hand row, the keys, taken in order from rear to front, bear respectively, ,the numerals 6, 7, f8, 9 and '0. The 'strip 42 is divided into two parts which may be separated by a central longitudinal line and. these two parts may be separated into compartments corresponding to the home positions of the nger .grip keys of the adjacent rows. At the left of the home positions of the 2, 3, 4 and- 5 keys are the groups of letters respectively. rlhis arrangement of the letters' of each group economizes space laterally.

At the right of the left-handrow of keys and opposite the home positions of 'the keys marked 166, 7, u8, H9 and o are the N, R, U, X and OPER O 77 S 7! VJ] M of which the parts are arranged in order downwardly. The arrangement is` in general-counterclockwise as for an ordinary dia-.1,-but instead of having the numerals on stationary parts with the letters, the numerals are on the movable nger pull keys. With this arrangement of the keys, the greatest movement required for the operating nger may be made substantiallyhalf of that required heretofore, and the nger grips move in straight lines instead of arcs.

Saidnger grip keys 35 and flush spacers`36-l of the right hand set (Fig. 2) lare pivotally connected by fpins the ends of which are supported in rollers 5I running in grooves 52 in left and right frame members 53 and 54 of a righthand unit 29a of the frame 29. At the front, the grooves 52 curve downwardly and rearwardly in the arc of a circle (Fig. 3) terminating in tangential parts extending to the rear. The finger grip keys 35 and iiush spacers 36 form part of a train including also six units 55 which are also `connected by pins 50 supported by rollers 5l in the grooves 52. The leading unit 55 is .pivotally connected by a pin 50 to a plunger 5l urged forwardly by a helical spring 58 to urge the finger grip keys 35 to their home positions.

The grooves 52 oi the frame members 53 and 54 of the right hand unit 29a extend substantially to the rear end of the path of the plunger 5l and the plunger is guided in upper and lower guideways with cylindrical guiding surfaces and separated sufficiently to permit the passage of the edges of units 55 therebetween. As illustrtaed, said upper guideway is provided by members 59 and 65 secured between frame members 53 and .54 by bolts 5l having their heads in countersunk recesses at the left face of members 53 and held in such position by nuts on the other endsof said bolts. Said lower guideway is .provided by members 52 and 63 secured between frame members 53 and 54 by means including bolts 64. vThe rollers 5| on the last pin 5D assist in holding said plunger 5l against tendency to oramp in said guideways. The plunger 5l may have side projections or at least partially closing the openings at the sides between upper members 59 and 60 and lower members 6I and 62. The frame members 53 'and 54' vand the guide members 59, 6U, 62 and 63 form a tubular assembly or tube ih which the plunger is reciprocated.

When any finger grip key 35 is pulled the train Vof keys 35, `spacers 36 and units 55, forces plunger 5l back against the action of spring 58 which is supported by a head :64a closing the right hand end (Fig. 3) of 'the guide for the plunger 57 and spring 58, the movement of the train vbeing stopped by Aengagement of the operat'ors iinger against a finger stop 65 (Fig. 3) at the forward end of the corresponding slot 34. When the nger is removed `from the finger grip key, the train returns to its Yoriginal position under pressure by spring L58, `being stopped by engagement of the -rearmost linger grip key with 'a bumper 56 of suitable material such as rubber. The plunger 51 may -serveas a dash pot speed regulator. Preferably, the adjustment vis such that when the rearmost linger grip key is pulled to the n'ger stop and released, the-train 're- `turns to its original position in about sevenfortieths of a second. This is about `the maximum speed and a lower speed is permissible.

Each finger grip key y3.5 is of suitable. material such., as metal or plastic and the upper surface ofv Ieach finger pull or key inclines 4outwardly from the. under surface from rear to front and at the front end turns abruptly outwardly to provide aprojection 5l (Fig. 6,) which facilitatesflnger gripping action. At the front end beneath said projection each finger grip key is cut out at each Yedge to form a central ear 58 with. a perforation to receivey a pin 50. At the rear 'end o-f eachffinger grip the central partis cutaway t0 provide two ears 69 spaced apart to recel-ve an ear 63 therebetween and withperforations aligned with that in said ear 58. `|The flush spacers 35 and the units 55 may be connected in the 'train in the same manner.

Said left frame 53 of the frame4 unit 29a includes a hub ln projecting to the right and the right Vhand frame 54 has a circular openingv v'll coaxial with a bore l2 extending through said hub lll and communicating with a countersunk recess 13 at the left of frame 53. Fixed in said bore 12, is a bearing 14 with its left endv flush with the bottom of said recess 13. Rotatably mounted in said bearing 14 isv a cylindrical part 14a of a rotatable member or shaft 15 which is held against movement to the right by engagement of the left hand end of said bearing 14 with the head of a screw 16, threaded into an axial bore in the left end of said cylindrical part 14a. As indicated in Fig. 3, the axis of said bearing 14 and shaft 15 is also the axis of said circular arc portions of grooves 52.

Just to the right of the right end of said bearing 14 is a short reduced portion 11 of said shaft providing a shoulder 18. At the right end of said reduced portion 11 is a shoulder 19 provided by further reduction in diameter to portion 80 screw-threaded from said shoulder 19 to its outer end.

Each of said nger grip keys 35 is provided at its inner face with a tapered recess 80a to receive a. tapered cog 8| of a plurality carried by a circular-arc ange 82 of a sector 83 having at its central point a perforation 84 to receive said short reduced `portion 11 and engage said shoulder 18. Said sector 83 is held against turning on said portion 11 by a flat 85 in the perforation 84 engaging a flat 86 (Fig. 9) on the shaft portion 11. As illustrated there are six cogs 8| and the rst ush spacer 36 to the front of `the keys is provided with a bottom recess 80a to receive the sixth cog 8 I.

For mounting on the circular arc flange 82 of the sector 83, each cog 6I may have a reduced portion 81 projecting inwardly through an opening in the ilange 82 and provided with a perforal tion 88 just at the inside of said flange, so that all of said cogs may be locked in position by passing a heavy wire 89 through said perforations and bending the ends of ,the Wire substantially` at right angles (Figs. 4 and 5).

Said sector 33 is held in place on the shaft portion 11 by means of a nut 90 (Fig. 9) screwed on the reduced portion 80 of said shaft 15. Outside of said nut 90 is an insulating sleeve 9| on said shaft portion 80 and mounted on this sleeve is a selenium rectier 92 comprising a diskelike element 93 and rectier brushes 94 and 95 electrically connected respectively to the left and right faces of said element 93. The insulation of said rectier element 93 and brushes 94 and 95 also includes washers 96 of insulating material. All of these parts are held in position by means of a long nut 91 having an external flange 98, a short cylindrical portion 99 at the outside of said flange and an externally threaded portion A sector |0| is loosely mounted on said cylindrical portion 99 of the nut 91 and is held thereon by a nut |02 engaging a shoulder at the right end of portion 99. Outside of said nut |02 is a sector I 03 rmly clamped against said nut by means including an outer nut |04. Independent movement of said sector I0| with reference to sector |03 is limited by means of a pin |05 fixed inA sector |03 and projecting through a slot I 06 in sector I 0|. Said sectors I0! and |03 are -provided respectively with sets of pins |01 and |08 which control certain contacts in a manner and for a purpose to be described hereinafter.

Said rectifier brushes 94 and 95 are preferably of thin spring metal and comprise respectively radial arm portions and flat springs I|0 and II I turned down sidewise and inwardly at right angles'to said arms. The radial arm or brush 95 is-shorter than that of brush. 94 and is displaced angularly to the rear so that part of spring III is spaced inwardly from spring IIO. At their outer ends these springs are formed with inwardly facing hooks, thus providing outwardly projecting contacts or contact portions |I2 and H3 adapted to ride in either direction along a commutator I|5 suitably mounted at the inner face of said circular opening 1I in frame 54.

The commutator II5 comprises a left-hand strip I I6 and a right-hand strip II1 illustrated diagrammatically in Fig. 10 as straightened and View from above, thus showing the faces opposite to those engaged by the brush springs |I0 and IIO respectively. Said left-hand strip II6 has a narrow continuous portion at its left from which project to the right a square tooth II8 at its upper end (Fig. l), a second square tooth I I9 of the same size and spaced therefrom a distance greater than the width of either of these teeth, and at the same distance from the second tooth I I9 a third tooth I 20 of the same Width but of less height than the others.

Said right hand commutator strip II1 comprises a narrow continuous strip at the right and projecting to the left thereof are, starting from the bottom, teeth |25, |26 and |21 corresponding to teeth II8, II9 and |20, except that tooth |21 is shown as somewhat higher than tooth |20. Opposite the tooth |21 is a member |30 and above said tooth |21 is a member |3I. Said members |30 and I3I have no electrical connection with the telephone apparatus or with each other but serve as supports for said brush contacts I I2 and I I3 when the commutator is not in use, thus keeping these contacts clean. Beyond the lower ends of the commutator strips II6 and II1 are corresponding members I32 and |33 which have no electrical connection with the commutator proper.

At the lower and inner faces of the commutator strips I6 and I|1 and associated members, the contacts I I2 and I I 3 will move downwardly in correspondence with the movement of a finger grip key 35, and upon release and during return the contacts will retrace their paths to their original or home positions. As illustrated, the commutator strip I I6 is directly connected to the a the circuit. y

Mounted on the right side of frame member 54 (Figs. '7, 8 and 9) are six contact springs desig- 2 nated from right to left by reference characters I4I, |42, |43, |44, |45 and |46. The rear ends of these springs are separated from each other and from said frame 54 by spacer-s of insulating material and are secured in position by means of screws |49 which are insulated from said springs. Each of said contact springs is provided at its rear end with a perforated ear (Fig. '1) for attachment to one of various Wires or conductors to be referred to hereinafter.

The spring I4I is provided with an inclined forward end I5I formed by bending the forward end of the spring to the left, thus causing a rear- Ward extension |52 ofi, the lower part ofthe bent 'andi to;v project t0 the right (Figs. 8v and 9).

A f-orwardlyfmoving pin |133 engagingV said in.- olinedend |5| atits'rear-Willmoue it to the right without closing or openingl any circuit` Howaver,y in thereturnmovement said pin' |33 will engage the forward facey olsaid inclined forward end |5| and move the spring, lv-i| to the left against spring |62 to close contacts Cr and force the. same to the lef-t., Such leftward movement of;A spring |;42, will act through an insulating pin or'post'v |53 on spring Ne to separate spring |45 from; spring M3 and' disconnect contacts C2.

The. spring |115 has an inclined, forward end |154- cQIr-esponding to; inclined end', |51 of, spring IM?. AL forwardly moving pin. mi? engagingl inclined; end` |565 in` its forward movement, will mately displace spring; |416 to the right, and move hast.; the.,` Same. On` itsl return movement, howeter, said pin |01 will engage the front face of said', inclined. end and move spring; M6 against spring |46 to close contacts C3;

The lengths of the inclined` ends ttl and |54 alle such that the corresponding springs,- lli and |1445- remain substantially in their operated positions while the nger train is returning, since as oneA pin;` drops,A oft, the next engages instantly.

The parte of' the left handv unit 26h are substantiallythelsameas :those of'` the right handunit but-.ate arranged in reverse,v order, thatv is from right to lef-t instead oifrom left to right. Also the corresponding parts oi the lett hand unit are designatedby the same numerals as the parts of the rghthand uint, but with the sunix h applied thereto..

The mannerV in which the pulses are produced willinow be consideredin connectionwvith Fig, l; Lifting of handset 26 from its cradle will cause closing of switches |60 and |6l. switch |26 short circuitsthe receiver and connects the c Wire to the-19, wire through an induction (milf |,62rleaid |263, the transmitter switchk |-6.|.-, lead |64, contact Spring- M3v carrying one off the contacts C2., contact spring |44 carrying the other Contact C2, lead. |65, spring Mtb; contacts Cab, contact spring Ulli-b and lead |66 to; the bwire.

Then upon pulling key m17 forwardA through twoingergripispaces, the finger ofthe operator strikes nger stop GEA-. During-this forward movement two pins |68 will wipe-pastinclined end. |5I offspring without: closing or opening any circuits-.v Due to its pin and slot' connection. with sector |63; sector il" willT be one step behind sector;` Milli and only onev piny itlwill w-ipe past inclined end |54 of spring |115/ during the for--` Ward. movement oir the` l key- Upon"- release of the "L" key; the tra-in will returnto its original position. During. this move.- mentthe two pinsk |'z08in advance of the inclined end will strike it in succession and' closely enough` together: to keep contacts Civ closed and contactslCz open until both of:l these pins have passedalong said inclined end. Due to the pin: and slotr connection, sector lillt will again drag behind and the forward pin lil'!I willi not engage inclined endA |51!y of contact spring- |45 until the second and last of the returning pins: ttt?` engages inclined end |5|v of spring MI.

During the same period the rectier brush contacts |2y and ||3 are advanced from members lgand |31 to parts |25? and E18-respectively and then returned. During the forward movements, therectier hasu no currentL to rectify; andthe sameis true for"thegfreturn'untilfit is connected in:,aiciric.11it. The cont-mts,l Crare; closed and the.

The closing; of

move the` brush spring contacts contacts Cr are open during the returnl move# mentlof, the pins: I-IJ-l As the trailing pins. |108 hold thev Ci contacts closed the. last pin |-.0'| closes.y the rectifier circuit and due to the position of4 therrectier brush con;- tacts: alt-this; time there Will be a single positive. pulse; set upintheline circuit. At this, instant, thev d wire;4 connected tothe b wire throughthe' right hand branch of, lead lwlet hand strip H6; of the commutator, the rectifier 92; the come mutator strip I lili, lead- |168", lead |69', contactsV G3; contact spring; M6', lead, 65; contacts. C211. contact spring |r44b-,. and lead: |66; The rectifier bruSlitcontacts-.pass immediatelyinto contact with members; |:3Ilf and 135|. respectively andthe rectiercircui-t. is: broken not only at. the commutator I5 but ati'fhecontacts Cs.

At this point it seems to be desirable to point outtherest of lthe circuit connections in` Figi. 10. Thef spring |4lf carrying one of the contacts Cris connect/edito one branch, ofv a lead |10A connected in= turn, to the: leadv |63 between the transmitter andi therreceiver switch. |16', the other branch being connectedi to spring Mib of.' the left hand unit carrying one ot the contacts Cib. 'I-liefspring |42 carrying: the otherl contact C1 is connected tol one branch ofiaf lead l'l't connected to a. lead |112 ofthel receiver circuitl just in advance of the receivenv the other: loranch'k being connected tothe spring |1412b carrying the other contact Cib.

The spring |42 is connected to the leadf |f64` and carriesy one of' the contacts-C2 which is normally in engagement with the` other contact C2 on spring |441. connected' to lead |65; At its other end lead |65? is: connected? to spring |1431) and through contactslCb, spring: Mib andflead |66 to the "hff wire orline. The spring |46' carrying one ofthecontacts C-is allso'cormectedf to the lead |65. The-springA IAEcarrying the other contact C: is connected to a lead tl-awhich in turn'is-connected' tospring Mibi During the returny movement of' the keys 35; the-spring UltY islmovedto the lef-t with the con tactsCi in engagement thus closing a circuit including the receiver; In this way spring |42 is forcedto the leftand' through saidpin |53 will move springf M'tdtheleft' and separate contacts Cif., thus breaking-z the circuit through the "af wire and` the b wire. Also, one or more pins |181' will press spring |45 to the left and cause engagement` of! the-contacts C3, thus connecting the rectifier andi the-commutator across between the a line and the lo line.

Pulling they 2 key to the finger stop 65" will |-l2` and |1|3i through three nger grip spaces to the commutator parts ||91andI |26 respectively; In the returny movement, there will be one idle stepbefore the recti'er circuit is closed at contacts Cx and then therewillbe-a negative pulse followed' by a= positive pulse. Pulling the 3 key to` the iinger'stopwill" move the brush springs ||`2 and* |i|3i to thef commutator parts |25 and |'|9 respectivelyv and on` the return movement'after release, thereVl willv be: one idle step followed byv pulses in the' order plus', minus, plus. For the 4 key, there would' be four pulses during its returny movement, in the-order minus, plus, minus, plus; and forI the-5 key theI return movement thereof pulses would be produced' in the order plus; minus, plus, minus, plus;

Referring to'Fig. 2f, the five iinger grip keys of the left-hand row. are designated' from topvtol bottom` as thery 6, 7; 8, 9, and 0 keys respectively; consequently, the 64 key whenl moved down to the finger stop 65h will pass through six finger grip or key lengths, which is the same as for the key at the right.

This means that there Will be ve pulses alternating between positive and negative, during the return movement of the 6 key. However, in the left hand commutator, the strip ll'lb is permanently connected to the a wire and the strip llb is connected to the b wire during the return movement of the key. Also the rectier 92h is arranged to pass current from brush contact ll2b to brush contact H3b. Consequently, the rst pulse will be negative and thel series of pulses will be minus, plus, minus, plus, minus.

For the 7 key the pulsing will be plus, minus, plus, minus, and for the 8, 9, and 0 keys the pulsing will be respectively minus, plus, minus; plus, minus; and minus.

The pulsing thus produced by the keys may be used to control key pulsing relays, digit counting relays, digit storing relays, etc. as disclosed for example in said co-pending application Serial No. 527,921, filed March 24, 1944.

It should be understood that communication or talking is eiiected by use of direct current but that upon the extension of a line to a distant point at which a selective control is to be exercised, a source of alternating current is coupled to the line thus enabling reversal of polarity in successive pulses. Such an arrangement is referred to in my co-pending application Ser. No. 583,478, led March 19, 1945, now Patent No. 2,434,910, which states that such an. arrangement is provided in my co-pending application, Ser. No. 523,626, filed February 24, 1944, now Patent No. 2,406,001.

Except for the change from positive pulses to negative pulses and vice versa, the pulsing action for the left hand apparatus is controlled in the same general manner as by the right hand apparatus.

In Figs. 12 through 20 there is illustrated another embodiment of the sender of the present invention in which the rectifier and other parts are turned by straight pull action from the keys. The arrangement of lingers grips or keys, so far as appears to the subscriber, is the same in general as for the first form., However, the fin'-vr ger grips of each row are attached to a exible member such as a cord or belt, or a thin metal band. The finger grip may be of any suitable* material interlocked with or attached to a flexible member. For example, the finger grips may be of metal, or of molded rubber or other semihard plastic molded to a tough flexible webbing of cotton or other suitable material.

Referring to Figs. 12 through 16 of the drawings, there is shown a casing or cover 33e. At the front of the casing, there are displayed two downwardly and forwardly inclined parallel rows of finger grip keys 35o of which the keys of the right hand row are shown in Fig. 12, and the keys of the left hand group are shown in Fig. 13. Each row of keys or nger grips 35e is part of a train which includes two flush spacers 36e (Fig. 12).

Said keys 35e and ush spacers 36C of each train may be of molded rubber or other semihard plastic. molded to a rough flexible cotton or other suitable textile webbing c providing exible hinge or pivotal connections between said Above the top key 35e of e' spring 58o to draw lthe rearmost and uppermost key 35e into engagementwith a bumper 66C of suitable material such as rubber. The band 50c might be attached directly to the rim 82e of the pulley 83e but preferably, for economy of space, use is made of a thin metal band Bic connected at one end to the band 50c and at the other end to said rim 32e at a point 56o. The webbing 50c may be made smooth and slippery by waxing or other treatment, and the edgesof each band 50c may be guided inside the set by metal U-shape` troughs '52e with ample clearance for turns at bendswhere the bands are turned downwardly and rearwardly. Between the troughs 52, the band 50c may be backed by suitable means which include the surface of the frame or one or more members 54o (Fig. 13) V'extending across said troughs at the inside thereof. 'y With the exception ofthe casing 33o, all of th parts just referred to may be supported on a central frame 29e having a base 30e, an uprightk 53e and a downwardly and forwardly inclined" portion 55o.

The pulley 83e includes not only the rim 82o but also va disk 84e `at the outer edge of theriin' and secured on shaft 15e. The inner end of ysaid shaft 15e is reduced, thus providing a' shoulderl 19o which engages the right end of a bearing llc' fixed in a bore in said frame 29e. To the right of said shoulder 19e said' shaft 15e has a screwthreaded portion 89o which extends for some distance. On this portion e 'of the shaft andv outside of a nut 90e' thereon are mounted they rotatable elements of a selenium rectifier V920 f Said rectifler'brushe's 94e and 95e have bent off" spring ends ll2c and H3C adapted to cooperate with a commutator H56 arranged in arcuate form on the side of frame 29e and properly in-ll sulated. This commutator corresponds to com.- rmutator H5 except' that it is arranged in an f of thedisk being engagedby anut Illilc'which cooperates with nut 98e to 'hold the pulley 83e.

fixed on the shaft 15e. Just to the outside of nut |080 the shaft 15o is again reduced providframe 29C.

The spring 58o whereby the pulley 83e is returned to home position, comprises coils extending around the shaft '15o and the ends of they spring are connected respectively to the bracket- I Ulc and the nut |8c in such a manner as to inserted in holes in nut I08c and bracket llllc.4

For adjustment purposes a plurality of holes (not: shown) may be provided to receive the ends of the spring.

Engaging the outer end of said bearing lllc' isahub |02c fixed on said shaft 15e by a. Seti- 211 screw .|030 and at its .inner end'provided with a latch-controlling arm |040. Just outside .of hub |010 ris a hub i050 which .carries .a =pointer or finger |060 which serves to control .the action of a plurality of contact springs 1|4|c, |420, |430, |4140, M50 and |460 (Figs. `13 and 171). Saidhu'b M50 -is pressed against hub y-llllcbyfrneans of .a spring .washer vH190 compressed against said hub |1050 .by a nut |:|.0.0. yOutsi'defof nut 4|-|.||c.is a`hub Irl lcheld in position-by a setscrew |40. Abent arm 42.80 extends radially from said 'hub I0 .and 'then horizontally to `the left or inwardly to extend across @the path vof l.the `pointer |060.

gIn home :position the pointer 060 rests against alstationary pin 129.0 projecting from the bracket `H110 (Fig. '16). `Wl1en the shaft 15e is turned cnunterclockwise by pulling keys `35e the pointer |060 will move with the shaft until it strikes a second .stationary pi-n |3140 fand 'is `rthus 'iheld against lfurther 'forward umovement-withithe shaft whichis frictionally .connected therewith. When thefshaft 1501s turned in the-opposite :or clockwise direction, the pointer moves rearwardly therewith #.until `it engages a flatch or stop iliillc. Then ithe Yfrictional Jconnection with shaft T50 permits -the shaft to .continue `the movement toward fits home position .although the pointer is held by s.the .latch irllllc.

4"When the latch-:controlling .arm |5040 vis returned .to a predetermined .position, the Ilatch Htc -.wil1 be 4Vreleased and vvthe pointer `will return with the :shaft to `home1position. 'Thismovemen't ofthe pointer to home .position is'assured bysaid bent arm 1.280. `With :the shaft '150 Ain its home position (Fig. 162), Athe 'latch-controlling arm |4140 .acting through vcertain elements about to beldescribed, holds saidla'tch |100 out of ithe-.path of the pointer :|3060 to enable `.the latter to .be swung forwardly :from Aits home position.

Said latch |||lcfis shown as ythe :outt-urned forward fend zof Aa vleaf spring |.1|.c of vwhich the rear end fis insulated from but supported on the bracket 113| 0. A bentarm .|'12c .preferably integral with spring |110, extends vupwardly 'from the .upper ledge .of said spring .and nto fthe `@left (illig. 13), -andfthen downwardly to a point where a cam `|130 :projects to the right ato .cooperate withlatch controlling arm 1040. The right 'hand edge of the `cam has `an outwardly and rearwardly inclined .edge which is the Apart engaged by said arm |040.

.The .spring x|410 `is controlled by the pointer or ringer 1| U60 and .to lrtlfrls end is :provided -with a'bentiarm |140 of at material which integral therewith 'and v.extends fromthe upper edge thereof to `the `right and then downwardly lto .the `forward fend of :a fiat cam |150 vertically on edge and inclined outwardly vto the rear. As viewed in illig.. 16 the scam is arcuate so that the area of .contact onpointer |060 willznot change. kWhen the pointer or pin |060 is swung forwardly, it engages the vleft suriace of cam xl'f'lc .and swings it .and the .forward end of contact .spring l|410 to the right in an idle movement as the pointer moves past this cam.

*..On the return movement, however, :said pointer upon engaging-the .right `face .of cam Tllc will 'swing spring 11H10 `to the left against spring |420 toclose .contacts .maand as the springs" i 410 .and |420 :move further to the left, a part .or yfinger |150? :oi insulating .construction mounted on spring |120 will engage spring llcand .separate it `from spring |440, thus separating contacts C2G. About one' ringer-pull Ikey- .distance .after closing :contants rCie. Spring A1450 will .rbc :mOi/ed t the left (Fig. 13) ftoengage spring l|460, thus .closing-'contactsCsc. This closingof the contacts Cac may be effected by means .of a llug lllc projecting upwardly from the rear-end of vcam i150 and carrying a fmger lil'c of .insulating character which engages :spring m50 and causes it to engage spring |450, thus closing contacts Cac.

When the -pointer i360 in .its return movement passes @off the'endofrcam H50, springs fillc, |420 and M30 return to their Ynormal or home .positions, and spring |450 is released from control by cam Hija. However, it is necessary to hold spring |450 in .engagement with the spring |460 while pointer |860 :swings .rearwardly .to .an vextent corresponding to a movement through one key space. To obtain this result, 'spring M50 is provided just tothe rear of the rear end of cam |150, with la bent arrn H extending from the top edge thereof tothe right (Eig. 13) 'and downwardly to the vlevel of the rear end oi cam |2150, Where it1supports the forward end of cam'member or cam |880 which extends rearwardly a distance corresponding to a keyrspace.

The greater part 'of cam |890 :from front Lto rear is kperpendicular to shaft :T50 .and normally lies in the path of pointer m60. At its rear end cam |800 has a part i8-|0 Vinclined outwardly so that the pointer |950 in its forward movement will cam to one side the-cam'member |890 lin an idle movement. As indicated vdiagrammatically in Rigs. .-1.8 and 19, ythe pointer |650, in its clockwise movement engages the lright hand cam |300 as it rides orf cam v5.50 land holds the contacts Cac closed until the `pointer passes through anotherfintervalcorresponding to a single 'key space.

The :operation of the springs I4! 0, i420, |430, |440, H550 and -c by the linger Ic is illustrated diagrammatically rin Figs. 17, 18, '19, the connectionoi these springs with leads |64, |65, |10., I-H and |12 of Fig. 'l0 `being shown in Fig. l'l.

,In Fig. 17., the home position `of pointer |660 is shown in a full circle to the right of cam fllc, and the dot-and-dash-circle at .the left indicates the position of the pointer when stopped in itsv forward :movement by member T340 (Fig. 16).

Fig. 18 illustrates the positions of the parts when 'the :pointer in its return movement has closed the .contacts Cm and is about to separate or fopen contacts C2G.

Fig. 19 illustrates the positions of the parts when the pointer has closed contacts Cie, opened contacts Cne'and closed contacts Cac. and is being held fby 'latch i780.

Fig. 20 illustrates the positions of the parts When the pointer after release from the latch me has .released :the cam |750 but still engages cam |800. As vthe pointer moves vfarther the cam |800 :is released :and the pointer reaches its home position aga-inst'member or 'stop lll l0.

With the exception of ythe left 'hand row of keys 3r5c and the associated flush spacers 360, the partsat'the ileft fof Fig. 13 vwhich are arranged in'opposite order are given the same numerals `as those at the =left but the subscript d is used in place of c.

The pulsing produced by operating the keys of the second form of the invention is the same as that 4produced by operating the keys of the rst form.

According to the irst form of `the invention, the plunger 5l (Fig. 3) serves as part of a dash pot .speed `regulator to prevent too rapid return of the 'keys `to their home positions.

According to the second form of the invention, a too lrapidl return .of the keys to ltheir'home positions 'isprevented (Fig. 12) by a braking device comprising a leaf spring '|c of which the rear end is secured to a bracket |82c fixed to the part 55e of the central frame 29o, and the forward end is formed with an upwardly convex portion llc to engage the lower face of said band 50c. Adiustment of the braking action may be effected by means of a set screw |82c passing through a` member |83c fixed on said bracket |820, and engaging the lower face of said spring 51o.

Although the cam |150 has been disclosed as acting through finger |`|8c to close contacts Cae, it is obvious that pointer |06c may act independently on spring I 45e by replacing cam |800 by one similar to cam |150 placed at a different distance from shaft e to prevent interference between the cams.

It will be seen that high speed rectier pulsing may be attained by use of the disclosed embodiments of the invention. y

Each form of the apparatus is made up of a right hand and a left hand unit, both of which can readily be mounted in a central support forming part of the frame. This arrangement provides for economical manufacture since the nal assembly on the subscribers set is limited to mounting two units on opposite sides of a frame, attachment of the finger trains, and adjustment of parts and connections.

It should be understood that various changes may be made, and that certain features may be used without others, without departing from the true scope and spirit of the invention.

What is claimed is: Y

1. In a circuit controlling device, a signalling circuit, keys corresponding respectively to digits 1 through 9 and 0, arranged in a plurality of rows, means for mounting said keys for movement longitudinally of said rows, a circuit closing device for each row of keys connected to said signalling circuit, and means for each row of keys and controlled by the longitudina1 movement of said keys for operating said circuit closing device and co-operating with it so as to permit current to'flow in said signalling circuit only in pulses of different combinations of successive different polarities, there being one combination for each key.

2. In a circuit controlling device, the combination, according to claim 1 wherein the keys are finger-grip keys in a plurality of longitudinally movable trains which control the pulse-combination-permitting means, and means is provided for limiting the finger pull movement of each train.

3. In a circuit controlling device, the combination according to claim 1 in which there are two rows of keys, the keys in the first row corresponding to digits 1 through 5 and those of the second row corresponding to digits "6 through 9 and 0. p

4. In a circuit controlling device, the combination, according to claim 3, wherein the circuit closing device and the operating means associated with the first row when controlled by the 1 key permits a single pulse of one polarity, when controlled by the 2 through 5 keys permits corresponding combinations of successive pulses of different polarities each ending in a pulse oi? the same polarity as for the l key, and the circuit controlling device and operating means associated with the second row of keys when controlled by the 0 key permits a single pulse of opposite polarity to that of the l key and that controlled by the 9 key through 6 permits respectively pulse combinations increas-` ing from 2 to 5 successive pulses of different' polarities, each ending in a pulse of the sameV polarity as for the O key.

5. In a circuit controlling device, the combinar tion according to claim 3 wherein there are two' trains of five keys each corresponding upwardly in the right train to digits l through 5 and downwardly in the left train to digits 6 through 9 and 0 and the pulse combinations permitted by the means variably operated by the keys ofi the right train run progressively from a single positive pulse for the 1 key up to five altermating-positive-and-negative pulses for the 5 key with the last pulse of each combination positive, and in the left train, the pulse combina-- tions from 6 down to 0 starting with five' alternating positive and negative pulses and' ending in a single negative pulse with the last pulse of each combination negative.

6. In combination, a signalling circuit, and

means connected to said circuit for permitting.

signals to be sent therethrough comprising a maximum of ve alternate positive and negativey pulses to a signal and corresponding to digits guided so as to exert thrust action, a rocking' member having a part of a cylindrical surface over which the forward part of said train passes and has a driving connection therewith, means for stopping each of said trains when any operating key reaches a certain position, and means for' returning said trains to home position.

'7. The combination, according to claim 6 wherein the cylindrical surface is provided with projecting cogs spaced to enter corresponding recesses in members of said train.

8. In combination, a signalling circuit, and.

means connected to said circuit for sending therethrough signals comprising a maximum of five pulses to a signal alternating between posi-f tive and negative and corresponding to digits "1 through "9 and 0, said sending means comprising side-by-side trains of finger-grip keys, means for stopping each of said trains when any finger-operated key reaches a certain posi' tion, means for returning said trains to home position, devices movable back and forth under control of said trains, dry rectifiers with brushes" movable with said trains, commutators over,v

which said brushes move for reversing the connections of said rectifiers in said circuit, and

means controlled by said devices for varying con' nections in said circuit during the return movements of the corresponding trains including connecting into said circuit the rectiers corre-v sponding respectively to the operated trains.

9. The combination according to claim 8v wherein the means for varying connections includes at each side six leaf springs of which the third and fourth are the only ones normally in contact with each other and the fifth and sixth are in the circuit of the correspondingv rectifier., and means operated by the corresponding device to close the contacts between the first and second springs, break the contacts between third and fourth springs, and close the contacts between the fth and sixth springs.

10. The combination according to claim 8" wherein the means for varying connections includes at each side six leaf springs of which only the third and fourth .are normally in con` tact and the fifth and sixth zare in the circuit of the corresponding rectier, means l'operated by the corresponding device to effect engagement of the-rst .and second springs and later engagement of the fth and sixth springs, and an insulating device interposed between one oi the first pair of springs and one of 'the second pair of vsprings whereby .the contacting vof the `first pair of .springs will -eiect disconnection ,of the ysecond pair vof springs before engagement between the fth and sixth springs.

:11. The combination according to lclaim 8 wherein the means for varying connections includes at each side six leaf springs of which only the third and fourth are normally in contact and the 'fifth and sixthare inthe corresponding rectier-circuit, an vinsulating device interposed lbetween 4one of the first two springs and one :of

the second pair of springs to disconnect the second pai-r of springs after connecting the rst pair, `cam ends on the first spring and =-one spring of the last pair, a member actuated by .the corresponding device Vand provided with ve pins engaging the -ca-m end of the first spring 4idly in one direction of vmovement but on the vreturn movement engaging the cam end on 'the other side :and pressing the firs-t spring against :the second and then separating the third and fourth springs, these conditions being maintained during the passage of the five pins, a second member carrying five pins acting on the vsecond cam end, and a `,lost motion connection between `the second member and the rst member whereby said rst member moves through .one key v'space before picking up said 'secondmemben 12. In combination, a signalling circuit, a lcircuit controller Vcomprising kvariably operable numerical pulse controlling means including two parallel trains of finger-grip keys, and 4two Vpivotally mounted rectiers in said 'circuit connected respectively to said `trains for control thereby.

13. The combination `according to claim 12 wherein v,each of said rectiers have brushes perpendicular Ito the pivotal `axis 4thereof and there is a curved commutator Vfor engagement by the outer ends yof `said brushes.

`14. The combination 'according to :claim 12 wherein fea-ch of said rectiiers .have brushes perpendicular to :the pivotal axis thereof and brush tips extending parallel to said iaxis, and there is `a curved commutator in `a plane perpendicular to zthe pivotal axis and 4sai-d brush tips engage said commutator.V

15. In combina-tion, a signalling :circuit and a circuit I'.zontrol'ler vcomprising two -reetifiers with brushes, `a two-strip -commutator for `each rectifier Aadapted to produce five successive pulses .alterna-ting between positive and negative, .and means to move the brushes of each .rectifier over the corresponding .fcommutator and off the opposite ends thereof, comprising two trains of Vve finger-grip vkeys .arranged side `by side.

16. In combination, a .signalling circuit, and means connected to said fcircuitforrsending therethrough signals .comprising Va maximum of .ve pulses to ya ,signal alternating between positive and negative and `corresponding to .digits l through,9 .and 0, said sending means .comprising side-by-side trains of finger-grip keys., means for stopping each of said trains when any finger-operated key reaches a certain position,

means for returningsaid .trains to home position, and circuit controlling means operable .by :said trains including two coaxial devices corresponding to said trains, a iiexible element connected to each train, a circular arc `rim on each :of `said. coaxial devices and having a driving connection with the corresponding element, va rectifier kwith brushes carried by each device, a `fixed .commutator over which said brushes travel back and forth, contact springs to control said circuit., and means including parts on said devices `to control said contact springs.

17. The combination according to claim .1.6 wherein each of said rectifiers is `within the ycor-- responding rim and the commutator is in a plane perpendicular to the axis 4of said devices.

18. The combination according to claim 1-6 wherein each contact-spring-controlling device comprises a member frictionally connected to the corresponding device for turning therewith .and cams connected to certain of said springs for `idle movement in one direction and active operation in the other.

19. The combination according to claim .16 wherein each contact spring-controlling device comprises a pointer, and there is a stop to :limit its movement away from its home position v.and enable it to act as soon as the corresponding `train starts its return movement.

20. The combination according to claim .16 wherein each group of contact springs includes springs with cams thereon, there is ra iinger frictionally held `on the corresponding device to operate said cams, and there is a Zla'tch to stop said finger 4at a given point in its return ,movement to maintain the finger in position with the cams in operated positions.

21. The 'combination according to claim 16 wherein each group of contact springs includes springs with cams thereon, there is a ringer frictionally held on the -corresponding device 5to operate said cams, there is a latch to stop 4said ringer at a given point in its return `'movement to maintain the finger in position with the .cams in operated positions, and'there is an Varm on said device to release said latch.

22. The combination according to claim lr6 wherein each group of contact springs includes springs with cams thereon, there is a nger frictionally held on the corresponding ydevice to operate said cams, there is a latch to stop said nger at a given point in its return movement to maintain the finger in position with the cams in operated positions, there is an arm on 'said device to release said latch, and means effective upon release of said latch for positively 'returning said finger to its home position.

GERALD DEAKIN.

REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS Number Name Date 1,251,495 Forsberg Jan. l, `1918. 1,835,256 Anderson Dec. 8, 1931 2,113,611 Bugge Apr. .12, .193.8 2,347,108 Hubbard Apr. 18, '1944 2,364,771 Bascom et al. Dec. 12, 1944 2,386,486 Mallina Oct. 9, 1945 '2,406,001 Deakin Apr. 20, 1946 

